We have a patch available for MDK2 for both the North American and Demo versions. A European patch with be coming next week. Simply hit the "Get Update" button on the MDK2 Launcher to patch your copy of MDK2.
For those of you who would rather do it manually, you can get the patch files below. If you are unsure what patch you need, just check the title bar of the MDK2 Launcher and it will list either 1000, 2000, 4000, or 9000.
Download these files and extract the contents into your MDK2 directory and run the Update.exe file, but select "Patch From File".